Gaseous electric discharge device



Oct. 10, 1933. G, GAlDlEs 1,930,099

GASEOUS ELECTRIC DISCHARGE DEVICE Filed May 12', 1931 INVENTOR ATTORNEY Patented Oct. 10,1933

-UllITED STATES PUATENT OFFICE 1,930,090 Gaseous "nnuc'mrcmsonaaon DEVICE .Georg Gaidies, Berlin-Pankow, Germany, assignor to General Electric Company, a corporation of New York Application May and in Claims.

The present invention relates to gaseous electric discharge devices generally and more particularly the invention relates to such devices in which the gaseous filling consists wholly or in 5 part of a. metal vapo It is well knownin the art that sodium and cadmium vapor are very eflicient gaseous fillings for gaseous electric discharge devices, however,

' it is as equally well known in the art that gas fillings of such vapors are destructive of the glass walls of the container ofthc device when the container consists of the usual glasses such as lead glass, magnesium glass and other well known glasses. Glass for use in the container of gaseous electric discharge devices, the gaseous atmosphere of which consists wholly or in part of a sodium or cadmium metal vapor, has recent- 12, 1931, Serial No. 536,803, Germany July 53, 1930 dined with an alkali metal vapor does not become noticeably browned or blackened after 1000 hours 5 of operation. I'he gaseous atmosphere of said electric discharge ,device consists ofsodium or cadmium vapor and may contain in addition a starting gas. At each end of container 1 is a stem 2 consisting of lead glass, lead 4 of electrode 70 5 being fused in said stem 2 to form a vacuum tight seal. A mica shield 6 is placed between ly been invented, and such glass is described in co-pending applications Serial Number 510,222, filed January 22, 1931, being the invention of Y Marcello Pirani, Martin Reger and Georg Gaidies, and Serial Number 470,436, filed July 24, 1930, being the invention of Georg Gaidies and Marcello 'The object of the present invention) is to provide means whereby the stem of the electric discharge device having a container made of the special glass described in the co-pending applications hereinbeiore referred to may be made of the usual sealing glasses, such as lead glass.

- The invention attains its object by providing shields of heat resisting material, such as mica, to form a baiile between the electrodes and the stems of the gaseous electric discharge device, said shields fitting against or closely approach- 'ing the walls of the container of the device to prevent the metal vapor from entering that part of the container in the region of the stem. The glass making up the stem is thus protected from the destructive efiects oi the sodium or cadmium vapor and as a resu t it may consist of the usual sealing glasses well known in the art.

In the drawing accompanying and forming part of this specification an embodiment of the invention is shown for purposes of disclosure.

Referring to the drawing 1 is the container or the gaseous electric discharge device, and said container 1 consists of a glass c emically stable in the presence of sodium or cadmium vapor. Such glass is disclosed in the can-pending applications referred to above and contains 2. considers,- ble percentage of iocric acid and the usual glass constituents such as alkalies, alkali earths and oxide together with less than 59% oi silicic acid. The boric acid part should always not less than 35% of all the stock parts of the stem 2 and electrode, 5, said shield 6 being maintained in pbsition by the slotted rim parts there-- of pressing against the inner walls of container 7 1 as shown inthe drawing, or said shield 6 may be'oflavite and the rim parts thereof may be iused into the walls of said container 1. That part of the container 1 in the region of the stem 2 is therefore, completely closedofi from the rest of the container 1 by shieldv 6 and thus the lead glass stem 2 is protectedrrom the destructive effects oi. the sodium or cadmium vapor,

While I have shown and described a particular embodiment of my invention it will be understood that many substitutions, modifications, and changes in the i'orm and details of the device may be made by those skilled in the art without departure from the broad spirit and scope or the invention, ior cizampleshield 6 may consist 01 any suitable heat resisting material and the electrodes 5 may be heated electrodes as shown or cold electrodes may be used as desired.

What I claim as new anddesire to secure by Letters Patent oi the United States, is: I

1. In an electric discharge device, a container having electrode supporting stems, electrodes sealed therein, a gaseous atmosphere therein, said container being of a glass resistant to the efiects of the gaseous filling, the stems of said container 1 being of a difierent glass and means interposed between said electrodes and said stems completely closing off the stem parts oi said container for preventing the gas filling from attacking the stems of said container.

2. in an electric discharge device, a container having electrode supporting ste electrodes sealed therein, a gaseous atmosphere of sodium vapor therein, said cont e: being ci a glass stems of said container being of a difierent glass and means interposed between said electrodes and said stems completely closing off the stem comprising a mixture of gas and a metal vapor,-

parts of said container for preventing the sodium vapor gas filling from attacking the stems of said container. 7

3. In an electric discharge device, a container having electrode supporting stems, electrodes sealed therein, a gaseous atmosphere of cadmium vapor therein, said container being of a glass resistant to the effects of the gaseous filling, the. stems of said container being of a different glass and means interposed between said electrodes and said stems completely closing off thestem parts of said container for preventing the cadmium vapor gas filling from attacking the stems of said container.

4. In an electric'discharge device, a container having electrode supporting stems, electrodes sealed therein, a gaseous atmosphere therein,

said container being of a glass resistant tothe effects of the gaseous filling, the stems of said container being ofadifierent. glass and'means interposed between said electrodes and said stems completely closing 05 the stem parts of said container for preventing the gas filling from at-- having electrode supporting stems, electrodes sealed therein, a gaseous atmosphere therein comprising an alkali metal vapor, said container being of a glass resistant to the eifects of the gaseous filling, the stems of said container being of adifferent .glass and a baffle interposed between said electrodes and said stems completely closing off the stem parts of said container to prevent the gas filling from attacking the stems of said container.

- GEORG GAIDIES. 

